1. Field of the Invention
The present invention relates to a sealed motor compressor containing a compressing element and an electromotive element for driving the compressing element in a sealed container.
2. Description of the Related Art
As a conventional electromotive element for driving a sealed motor compressor forming a freezing cycle of a refrigerator (freezer), or an air conditioner, an induction motor driven by a single-phase commercial power source, DC brushless motor, and the like have been employed. An electromotive element of the motor is fixed in a sealed container, and the electromotive element is formed of a stator comprising a stator winding, and a rotor rotating in the stator. Moreover, the electromotive element supplies a commercial alternating current supply to the stator winding to induce/rotate the rotor.
However, the DC brushless motor requires a drive control equipment, and disadvantageously results in a cost increase. Moreover, because a secondary copper loss is theoretically present in the induction motor, running efficiency is limited. Therefore, there has been a desire for further improvement of the running efficiency of the sealed motor compressor driven by the commercial single phase power source without using any control equipment.
Moreover, there has been a desire for development of the sealed motor compressor in which he electromotive element using a three-phase power source can be driven with a high efficiency without requiring any drive control equipment.
The present invention has been developed to solve such related art problem, and an object thereof is to provide a sealed motor compressor whose single-phase bipolar construction largely enhances a motor running efficiency.
Another object of the present invention is to provide a sealed motor compressor in which an electromotive element with a three-phase bipolar construction can be driven with a high efficiency without requiring any drive control equipment.
That is to say, according to the present invention, there is provided a sealed motor compressor containing a compressing element and an electromotive element for driving the compressing element in a sealed container. The electromotive element is fixed to the sealed container, and formed of a stator provided with a stator winding and a rotor which rotates in the stator. The rotor comprises a squirrel-cage secondary conductor disposed in a peripheral portion of a rotor yoke, and a permanent magnet embedded in the rotor yoke.
Moreover, for the sealed motor compressor of the present invention, in the above, the electromotive element comprises a single-phase bipolar construction.
Furthermore, for the sealed motor compressor of the present invention, in the above, the electromotive element is started by a system using a startup capacitor.
Additionally, for the sealed motor compressor of the present invention, in addition to the above, the stator winding comprises a main winding and an auxiliary winding, and a winding ratio of the respective windings by effective winding number calculation is set to be in a range of 1.0xc2x10.5.
Moreover, in the sealed motor compressor of the present invention, the squirrel-cage secondary conductor of the rotor comprises a skewed structure.
Furthermore, for the sealed motor compressor of the present invention, the permanent magnet is a rare earth magnet.
Additionally, for the sealed motor compressor of the present invention, the number of permanent magnets embedded in the rotor yoke is any number selected from the group consisting of two, four, six and eight.
Moreover, the sealed motor compressor of the present invention further comprises current-sensitive protection means for detecting a line current.
Furthermore, according to the present invention, there is provided a sealed motor compressor containing a compressing element and an electromotive element for driving the compressing element in a sealed container. The electromotive element is driven by a three-phase power source, fixed to the sealed container, and constituted of a stator provided with a stator winding and a permanent magnet embedded type rotor which rotates in the stator. The rotor comprises a squirrel-cage secondary conductor disposed in a peripheral portion of a rotor yoke, and a permanent magnet embedded in the rotor yoke.
Moreover, for the sealed motor compressor of the present invention, in the above, the electromotive element comprises a three-phase bipolar constitution.
Furthermore, in the sealed motor compressor of the present invention, the squirrel-cage secondary conductor of the rotor comprises a skewed structure, and a skew pitch is more than 0, and is 1.5 slot pitches or less.
Additionally, for the sealed motor compressor of the present invention, the permanent magnet is a rare earth magnet.
Moreover, for the sealed motor compressor of the present invention, the number of permanent magnets embedded in the rotor yoke is an even number.
Furthermore, the sealed motor compressor of the present invention further comprises current-sensitive protection means for detecting a line current.
Additionally, for the sealed motor compressor of the present invention capability control is enabled.